Effective separation and recovery of valuable metals from copper slag: A comprehensive review

Copper slag, a secondary product generated from the copper refining process, which contains an extensive amount of valuable metals and harmful elements such as Fe, Cu, Zn, Co, Ni, Pb, As, etc. The massive accumulation and limited value-added utilization of copper slag have caused serious environmental pollution and resource waste. In order to realize the resourceful and high-value comprehensive utilization of copper slag, the efficient separation and recovery of valued metals from copper slag has garnered significant attention. In this work, a review of the extraction and recycling processes for valued metals from copper slag was presented, and the production process, physicochemical properties, and microstructure of copper slag were introduced. Several typical processes for the separation and recovery of valued metals from copper slag have been thoroughly compared and summarized, including flotation, pyrometallurgical, and hydrometallurgical methods. In addition, the current development status of extracting valuable heavy metals from copper slag was analyzed, and the main challenges it faces were summarized and discussed, aiming to promote the resource utilization and high-value utilization of copper slag.